Treatment of a large superficial basal cell carcinoma with 5% imiquimod: a case report and review of the literature

Nanoemulsions and nanoparticles for non-melanoma skin cancer: effects of lipid materials

Basal cell carcinomas and squamous cell carcinomas are non-melanoma skin cancers reported to be among the most common malignancies, being responsible for high human morbidity. Conventional chemotherapy applied to these conditions shows non-specific targeting, thus severe adverse side effects are also commonly reported. New therapeutic strategies based on nanoparticulates technology have emerged as alternatives for site specific chemotherapy. Among the different types of nanoparticulates, lipid nanoemulsions and nanoparticles have several advantages for topical delivery of poorly soluble chemotherapeutics. These particles show sustained drug release and protection of loaded drugs from chemical degradation. This technology is promising to enhance the intracellular concentration of drugs and consequently reduce the cytotoxicity of skin chemotherapy.

Nonsurgical treatment options for Basal cell carcinoma

Basal cell carcinoma (BCC) remains the most common form of nonmelanoma skin cancer (NMSC) in Caucasians, with perhaps as many as 2 million new cases expected to occur in the United States in 2010. Many treatment options, including surgical interventions and nonsurgical alternatives, have been utilized to treat BCC. In this paper, two non-surgical options, imiquimod therapy and photodynamic therapy (PDT), will be discussed. Both modalities have demonstrated acceptable disease control rates, cosmetically superior outcomes, and short-term cost-effectiveness. Further studies evaluating long-term cure rates and long-term cost effectiveness of imiquimod therapy and PDT are needed.

Management of superficial basal cell carcinoma: focus on imiquimod

Superficial basal cell carcinoma comprise up to 25% of all histological sub-types. They are more likely to occur on younger persons and females and although generally more common on the trunk, also occur frequently on the exposed areas of the head and neck especially in areas of high sun exposure. In the last decade, new treatment options such as topical applications that modify the immune response have been trialed for effectiveness in treating these lesions. Imiquimod 5% cream has been shown to stimulate the innate and cell mediated immune system. The short-term success of imiquimod 5% cream in randomized controlled trials comparing different treatment regimes and dosing as a treatment for small superficial basal cell carcinoma (BCC) not on the face or neck is in the range of 82% for 5 times per week application. A high proportion of participants with good response rates to topical treatment (58%–92%) experience local side effects such as itching and burning, less commonly erosion and ulceration, but the proportion of participants ceasing treatment has not been high. To date one long-term study indicates a treatment success rate of 78%–81% and that initial response is a predictor of long-term outcome. Recurrences tend to occur within the first year after treatment. Future research will compare this preparation to the gold standard treatment for superficial BCC – surgical excision.

Basal cell carcinoma: treatment with imiquimod

BACKGROUND

Basal cell carcinoma (BCC) is the most common cutaneous malignancy. There are various approaches to its treatment, but imiquimod, the immune response modifier, offers a topical, noninvasive, nonsurgical therapeutic option.

METHODS

We present our experience of the treatment of 96 patients with BCCs during the period March 2002 to February 2004 at the Dermatology Department, Hospital Clínico S. Cecilio, Granada, Spain. One hundred and forty-one tumors (nodular, superficial, and pearly/ulcerated clinical types) were treated with imiquimod.

RESULTS

The clinical cure rate at 12 months was 80-85%.

CONCLUSION

Our experience indicates that imiquimod is a reasonable option for the treatment of BCC. It is low cost, can be delivered via ambulatory care, and has tolerable side-effects.

Molecular aetiology and pathogenesis of basal cell carcinoma

Recent insights into the cell biology of the epidermis and its appendages are transforming our understanding of the pathogenesis of basal cell carcinoma (BCC). The significant progress that has been made warrants a comprehensive review of the molecular and cellular pathology of BCC. The items addressed include environmental and genetic risk factors, the biology of the putative precursor cell(s), and the contribution of aberrations in processes such as apoptosis, cell proliferation, differentiation and signalling to carcinogenesis. Furthermore, established and novel treatment modalities are discussed with particular attention to future biological approaches.

Imiquimod for the treatment of skin cancer

Imiquimod is a topically applied immunomodulator. Although initially approved for genital and perianal warts, dermatologists have prescribed this compound for many neoplastic and nonneoplastic skin conditions. The US Food and Drug Administration recently approved imiquimod for the treatment of actinic keratoses. This article reviews the literature on imiquimod in the treatment of cutaneous malignancies.

Awareness of, knowledge of and attitudes to nonmelanoma skin cancer (NMSC) and actinic keratosis (AK) among physicians

BACKGROUND

Nonmelanoma skin cancer (NMSC) is the most common type of cancer that affects the Caucasian population. Approximately 80% of NMSCs are basal cell carcinoma (BCC) and 20% are squamous cell carcinoma (SCC). Actinic keratosis (AK) is a precancerous lesion that may develop into SCC.

METHODS

A market research survey was conducted in which dermatologists and primary care physicians (PCPs) were randomly selected from seven countries (USA, Australia, UK, Italy, France, Germany and Spain). Their knowledge of nonmelanoma skin cancer and their current clinical practice were assessed.

RESULTS

In total, 2100 physicians took part in the survey. They had practised medicine for between 1 and 30 years and saw at least 30 patients in a typical week. The majority of dermatologists (97%) were familiar with BCC and AK, and treated each condition with a minimum of referrals. PCPs were more familiar with BCC (90%) than with AK (74%). Of the PCPs that were aware of BCC, only 31% treated the condition, and of those aware of AK, 40% treated the condition. Surgery was the most common choice of treatment for BCC. The most popular treatment choice for AK lesions was cryotherapy. Eighty to 100% of physicians reported that they discussed skin cancer prevention with their patients. A much lower number of physicians (ranging from 5 to 37%) provided educational material to patients. Overall, PCPs in the two countries that have a high incidence of NMSC (USA and Australia) were more familiar with BCC and AK and more likely to treat each condition than PCPs in Europe. All physicians rated BCC as a more serious condition than AK. Facial lesions were considered more serious than lesions on the head or trunk for both conditions.

CONCLUSIONS

As the burden of disease and the number of patients seeking treatment for NMSC increase, dermatologists are well placed to lead educational initiatives for PCPs and provide educational material for patients. This would increase awareness of AK and BCC and could improve early diagnosis.

Topical Imiquimod Treatment for Nodular Basal Cell Carcinomas: An Open-Label Series

BACKGROUND

Imiquimod has been used for basal cell carcinomas (BCCs). This is the first open-label series using imiquimod for nodular BCC with Mohs surgery resection for confirmation of treatment.

OBJECTIVE

To evaluate the efficacy of topical imiquimod in patients with biopsy-proven nodular BCC.

RESULTS

After 12 weeks for three times a week application, treatment sites at week 15 were surgically excised using Mohs micrographic surgery. All 15 treatment subjects were clear of BCC. At the 18-month follow-up, no patients had recurrent tumor.

CONCLUSION

Imiquimod 5% cream may be another treatment modality for nodular BCC.

Immunotherapy of basal cell carcinoma: evolving approaches

Nonmelanoma skin cancer (NMSC) is one of the most common types of cancer in the world. There is strong evidence that ultraviolet (UV) light plays a central role in the molecular pathogenesis of NMSC development. UV light causes DNA damage and loss of activity of tumor suppressor genes and overexpression of oncogenes and other genes related to enhanced growth and survival as well as tissue invasion. Also, UV light impairs the cutaneous immune response, especially Langerhans cell antigen-presenting function, resulting in immune tolerance to developing tumor cells. Standard treatments for NMSC include surgical excision, curettage and electrodessication, and Moh's micrographic surgery. Immunotherapy of NMSC has been attempted in the form of dinitrobenzene sensitization followed by topical application on the tumor, intralesional interferon injections, or perilesional interleukin-2. These treatments, although showing promise, have not been developed because of lower efficacy compared with surgical approaches, morbidity associated with treatments, as well as the expense of using recombinant cytokine treatments. The topical immune response modifier imiquimod is being developed as a novel local treatment for selected NMSC. Studies of the mechanism of action of imiquimod in NMSC indicate the presence of activated, natural killer cells (innate immunity), T-lymphocytes (adaptive immunity), antigen-presenting cells, and cytokines consistent with a delayed-type hypersensitivity reaction (Th1-lymphocyte cytokine pattern). This agent has been associated with a high response rate for the treatment of superficial basal cell carcinoma, with clearance rates ranging from 70% to 90% in a number of clinical trials. This novel immunotherapy represents a new, nonsurgical treatment option in the care of patients with NMSC.

Imiquimod to treat different cancers of the epidermis

BACKGROUND

Topical immunomodulatory therapy with imiquimod has been recently used for the treatment of actinic keratoses, intraepithelial carcinoma, and small basal cell carcinoma (BCC) besides the licensed indication of extragenital warts (condyloma).

METHODS

We treated several patients with particular epidermal neoplasias such as squamous cell cancer (SCC) and basal cell cancer of sclerodermiform type three times per week for 4 to 12 weeks.

RESULTS

We report several novel aspects of the treatment of epidermal cancers with self-applied, nonpainful, immunomodulatory therapy. First, we treated-for the first time-two immunosuppressed renal transplant patients for invasive SCC with imiquimod. Interestingly, systemic immunosuppression did not adversely affect the response to therapy. Second, one patient with the high-risk and aggressive growth pattern of basal cell cancer (sclerodermiform histology) was cured from his disease at a particular location in the face, suggesting sufficient penetration despite scarring. No recurrence was detected in another patient who suffered from 29 BCCs until almost 2-years follow-up. Third, the treatment of actinic keratoses in the face is substantially shorter (in the order of 4 to 6 weeks) as opposed to other skin cancers. Immunomodulatory treatment with imiquimod led to the demarcation of in situ actinic keratosis lesions that could not be identified using the dermatologist's experience, probably because of the existence of exclusive alterations on the molecular level.

CONCLUSION

Several novel aspects of immunomodulatory treatment with imiquimod and new indications such as selected cases of sclerodermiform BCC and SCC have been described. The texture of the skin at various different body locations may explain the varying sensitivities to imiquimod when facial skin is compared with skin on the extremities.